I gather this is a pretty common occurrence, judging by the amount of chatter I see. Sometimes I go for days without it happening, sometimes it occurs several times in an hour. Usually when it occurs, when I close the error dialog, explorer shuts down, closing all open explorer windows and closing the taskbar, which appears again after a little while. I'm fairly certain this is due to something associated with right-clicking on a file - i.e. a 3rd party app that has installed something on context menu.

Is there any simple way of finding out who the culprit is? I really don't want to uninstall all my cruft and reintroduce it bit by bit, because the problem is not reproducible enough for me to know if the problem has returned.